uh, the reason toyota didn't do that is because the 22R head is more emissions-friendly. the 20R head will let you rev higher but won't really do much for torque.
that's like saying, if toyota designed the pickup with push pull steering, you wouldn't believe in crossover 
Didn't that setup actually come stock on supra's? you know 22r block with a 20r head?
sorry for the thread jack...
